Science : Ch 11 – The Human Eye and the Colourful World

Which of the following statements is correct regarding the propagation of light of diferent colours of white light in air?

The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light:

The sun appears red at sunset or sunrise. Choose the incorrect statement from the following

A student traces the path of a ray of light through a triangular glass prism for diferent values of angle of incidence. On analysing the ray diagrams, which one of the following conclusions is he likely to draw?

Power of a lens is the measure of the degree of

When sunlight passes through a canopy of a dense forest, tiny water droplets in the water scatter light.This is an example of

The sky appears black to an astronaut

The density of the atmosphere, as we know goes on decreasing as the distance above the sea level increases,this phenomeneon is called

The defect in a person can see nearby objects but not far away objects

When a person can see faraway objects but not nearby objects.

Astigmatism can be corrected

The SI unit of Power of a lens is

The emergent ray in a prism bend at an angle to the direction of the

The colour of the clear sky blue due to

The refractive index of glass is largest for